In answering whether or not birth control was permissible for a woman who used it for medical purproses, Ms. Arnold stated it was okay so long as it was not used for contraceptive purposes. My understanding of our faith is that this answer is mostly correct but misses a slight nuance.

In the case where a woman uses the Pill for medical purposes, but is sexually active, my understanding is that it is no longer permissible to use the Pill, despite the woman's legitimate medical rationale for needing to take it. Is my understanding correct?

Answer by Catholic Answers on 11/21/2012:

J.S.--

No, it is not correct. A drug taken for legitimate medical purposes may be taken for those purposes even if the drug has side effects that are not intended or willed by the patient.

As an analogy, let us suppose a man with a heart condition needs a certain kind of drug for his heart condition that has the side effect of causing temporary sterility. He can use that drug for his heart condition, he can even engage in marital relations with his wife though those relations will not be "fruitful," so long as he does not will or intend the negative side effect of sterility. But if there is another comparable treatment for his heart condition that does not have the same negative side effect of sterility, then he should consider using the alternative treatment.

In like manner, a woman who needs a drug ordinarily used for contraceptive purposes for another legitimate medical condition can use that drug for the medical condition so long as the negative side effect of temporary sterility is not intended or willed. So far as I am aware, there is no legislation by the Church that requires her to stop marital relations with her husband while on the drug. If she and her husband choose to abstain from marital relations because they fear other side effects of the drug (such as its potential to act as an abortifacient), they may do so, but that is a prudential judgment on their part and not something "commanded" of them by the Church. Those who would say otherwise have the burden of substantiating that assertion from the authoritative documents of the Church.